Before dawn, General Robert E. Lee had arrayed his Confederate Army of Northern Virginia with Major General Thomas J. “Stonewall” Jackson’s men on the north (left), and Major Generals James Longstreet’s and D.H. Hill’s Confederates in the center and right. The small remainder of Lee’s command held the extreme right (south) until Jackson’s remaining division under Major General A.P. Hill could arrive from Harpers Ferry, 17 miles away.
Dawn broke gray and ominous. Pickets advanced cautiously in the mist and fog, until they came across each other and started firing. Soon both armies were up firing on each other, and it would continue for the rest of the day. Heavy combat began around 5:30 a.m. as Major General Joseph Hooker’s First Federal Corps advanced on the Hagerstown turnpike and attacked Jackson’s men in the fog. The Federals hoped to seize the ground around the Dunker Church and turn the Confederate left.
Federals drove the first Confederate line out of the North Wood and into an area later known as the Cornfield. A Confederate counterattack led by Brigadier General John Bell Hood’s hard-fighting division pushed the Federals back to the Miller farm, with the lines surging back and forth over a dozen times.
Hooker later reported that “every stalk of corn in the northern and greater part of the field was cut as closely as could have been done with a knife, and the slain lay in rows precisely as they had stood in the ranks a few moments before.” Hooker was shot through the right foot and had to be taken from the field due to loss of blood. Major General James Ricketts was next in line to replace Hooker, but McClellan heeded Hooker’s advice and instead replaced him with Brigadier General George G. Meade.
Major General Joseph K.F. Mansfield’s Federal Twelfth Corps then charged along Hooker’s left, moving through the East Wood and making a stand north of Dunker Church. Mansfield came up to men of the 10th Maine and, thinking that they were inadvertently firing into Hooker’s men, told them to stop firing. A soldier later explained, “Those that were firing at us from behind the trees had been firing at us from the first.” Mansfield stepped up to get a closer look and said, “Yes, yes, you are right,” just before he was shot in the chest. Mansfield had only been in command for two days, and he died the next day.
Major General Alpheus Williams, whom Mansfield had replaced as corps commander, now retook the Twelfth Corps. He wrote McClellan, “Genl Mansfield is dangerously wounded. Genl Hooker wounded severely in foot. Genl (Edwin) Sumner I hear is advancing. We hold the field at present. Please give us all the aid you can. It is reported that the enemy occupy the woods in our advance in strong force.”
Major General John Sedgwick’s division advanced in the lead of Sumner’s Second Corps around 9 a.m. Sedgwick believed that the Federals had captured the field and was going in to secure the victory, but he soon realized that too many troops were tending to the wounded. One of his colonels noted, “When good Samaritans so abound it is a strong indication that the discipline of the troops in front is not good and that the battle is not going so as to encourage the half-hearted.”
Sumner led Sedgwick’s division forward, unaware that his other two divisions were not following as they had been ordered. Sedgwick’s force was formed into three lines, which was designed for a head-on fight but not at all prepared to withstand a flank attack. When Confederates poured artillery into the lines, a survivor wrote, “We were as easy to hit as the town of Sharpsburg.” Confederate reinforcements led by Major General Lafayette McLaws and Brigadier General Jubal Early then slammed into the Federals and sent them reeling. Sedgwick shrugged off a wound in his arm, but a second bullet knocked him off his saddle and put him out of active duty for several months.
McClellan’s plan to attack with overwhelming numbers turned into uncoordinated attacks that failed to reach their maximum impact. This enabled Lee to shift his troops from his right to reinforce Jackson on the left. The Confederates held their ground, but Federals repelled a final counterattack. Fighting subsided around 10 a.m. with over 8,000 casualties inflicted in the northern sector of the field alone, including two Federal corps commanders.
A new fight soon erupted farther south, where Brigadier General William French’s division of Sumner’s corps veered away from the fighting to the north and confronted D.H. Hill’s 5,000 Confederates along a sunken road. French sent his troops against the Confederates one brigade at a time, and they were all repelled within an hour, sustaining 1,750 casualties out of 5,700 men.
Lee committed his last division in reserve, 3,400 men under Major General Richard H. Anderson, to Hill’s right, around 10:30. By that time, Major General Israel Richardson’s 4,000-man division under Sumner came up on French’s left. Federal troops eventually surged through a gap in the line caused by a Confederate officer mistakenly pulling out a regiment.
The Federals then opened a murderous enfilade fire on the defenders along the road. A sergeant of the 61st New York said, “We were shooting them like sheep in a pen. If a bullet missed the mark at first it was liable to strike the further bank, angle back, and take them secondarily.” The road was later called “Bloody Lane.”
The Federals were on the verge of breaking the Confederate line when Longstreet brought up artillery. A Confederate artillery shell fragment wounded Richardson, who said, “Tell General McClellan I have been doing a Colonel’s work all day, and I’m now too badly hurt to do a General’s.” Richardson lingered 47 days before dying. Just as Hooker’s wounding had stalled Federal momentum in the northern sector, Richardson’s wounding stalled the center. Some 5,600 total casualties were sustained along the sunken road from 9:30 a.m. to 1 p.m.
McClellan held some 20,000 Federals in reserve that could have been used to split Lee’s army in two. Major General George Sykes offered to lead these men in a charge through the Confederate center, but McClellan turned him down. The Federal commander missed a golden opportunity to destroy the Confederate army. McClellan wrote his wife that afternoon, “We are in the midst of the most terrible battle of the age. So far God has given us success but with many variations during the day.”
McClellan notified his superiors at 1:25 p.m.: “We are in the midst of the most terrible battle of the war, perhaps of history–thus far it looks well but I have great odds against me… I have thrown the mass of the Army on their left flank. Burnside is now attacking their right.”
Action shifted to the weakened Confederate right, which was opposed by Major General Ambrose E. Burnside’s Ninth Corps. Burnside had received a directive from McClellan at 9:10 a.m. to capture the bridge spanning Antietam Creek, “gain possession of the heights, and to advance along their crest upon Sharpsburg and its rear.” McClellan assured Burnside that once he seized the ground west of the Antietam, “you will be supported.”
With action stalled in the northern and center sectors of the field, all depended on what would happen to the south. A reporter for the New York Tribune wrote, “All hazard of the right being again forced back having been dispelled, the movement of Burnside became at once the turning-point of success and the fate of the day depended on him.”
By early afternoon, Burnside moved to cross the creek after various delays. He directed his men to cross Rohrbach’s Bridge, even though the Antietam was only waist deep at various spots beyond Confederate range. The Federals were held up several hours at what became known as Burnside Bridge, allowing Lee to send more reinforcements to his left and center.
Meanwhile, other Federals struggled through brush to find Snavely’s Ford, about two miles downstream. They finally began wading across in early afternoon, around the time that the Confederates guarding the bridge were running low on ammunition. With Federals now on their flank, the Confederates withdrew, having stalled Burnside’s main advance for over three hours.
Burnside prepared to pursue the Confederates, but he was delayed two hours by ammunition and supplies being funneled across the creek on the narrow bridge. This gave Lee time to reinforce his right. Burnside planned to turn Lee’s right and block Boteler’s Ford, Lee’s only escape back to Virginia. But by this time, A.P. Hill’s 3,000-man “Light Division” was crossing the ford to bolster the flank. Hill’s men had been marching since 7:30 a.m., and they arrived just in time to save Lee’s army.
McClellan, having kept his cavalry in reserve, was unaware that the Confederates were being reinforced and thus did nothing to counter the threat. Hill slammed into the Federal left, prompting Burnside to order a withdrawal all the way back to Antietam Creek. When he called for the reinforcements that he had been promised, McClellan sent his cavalry commander, Brigadier General Alfred Pleasonton, with a message at 3:30 p.m.: “General McClellan directs me to say he has no infantry to spare.”
Burnside made another desperate plea for more men. Although McClellan had the Fifth and Sixth corps under Major Generals Fitz John Porter and William B. Franklin in reserve, he told the messenger, “Tell him if he cannot hold his ground, then the bridge, to the last man!–always the bridge! If the bridge is lost, all is lost.” When the fighting ended around 5 p.m., Burnside’s men held the bridge.
Both sides sustained a combined total of 26,193 casualties in the most terrible single day of the war. The Federals suffered 12,469 losses (2,010 killed, 9,416 wounded, and 1,043 missing) out of about 75,000 effectives, while the Confederates lost 13,724 (2,700 killed, 9,024 wounded, and 2,000 missing) from roughly 40,000. Casualties were inflicted at the rate of about 2,200 per hour. The Federal Black Hat Brigade, recently nicknamed the “Iron Brigade,” lost 42 percent of its strength.
Medical personnel hurried to tend to the wounded; they turned nearby houses, churches, barns, and other buildings into makeshift hospitals. Local women volunteered as nurses. Doors were ripped from hinges to serve as operating tables. Surgeons worked nonstop through the night without washing their hands or instruments before going from one patient to another. A U.S. Sanitary Commission worker reported:
“Indeed there is not a barn, or farmhouse, or store, or church, or schoolhouse, between Boonesville, Sharpsburg, and Smoketown that is not gorged with wounded–Rebel and Union. Even the corn-cribs, and in many cases the cow stable, and in one place the mangers, were filled. Several thousands lie in open air upon straw, and all are receiving the kind services of farmers’ families and the surgeons.”
McClellan demonstrated his tactical ineptitude yet again by never committing more than 20,000 men to the fight at any one time. This helped Lee thwart the many Federal attacks, despite being outnumbered. Antietam was one of the war’s few battles in which both commanders chose the battlefield and planned their tactics in advance. It was also the first battle that Lee directed from start to finish. Although the Confederates had not won, Lee skillfully directed reinforcements to points on the line where and when they were needed most, which prevented his army’s collapse and possible destruction.
Not only did the Confederates hold their ground against vastly superior numbers, but Lee even proposed to counterattack the next day. Lee believed an attack could succeed based on McClellan’s chronic lack of aggression. But after receiving his commanders’ reports and determining that he had no more than 30,000 men left, Lee decided that he could not renew the contest, especially with his back to the Potomac River. Even so, he defiantly held his ground and waited for McClellan to renew the battle on the 18th. McClellan characteristically declined.
- Anderson, Nancy Scott; Anderson, Dwight, The Generals: Ulysses S. Grant and Robert E. Lee. New York: Vintage Books, 1987.
- Angle, Paul M., A Pictorial History of the Civil War Years. New York: Doubleday, 1967.
- Bailey, Ronald H., The Bloodiest Day: The Battle of Antietam. Alexandria, VA: Time-Life Books, 1983.
- Catton, Bruce, The American Heritage Picture History of the Civil War. New York: American Heritage Publishing Co., 1960.
- Catton, Bruce, The Army of the Potomac: Mr. Lincoln’s Army. Garden City, NY: Doubleday & Co., Inc., 1951.
- Catton, Bruce and Long, E.B. (ed.), Terrible Swift Sword: Centennial History of the Civil War Book 2. New York: Doubleday & Company, Inc. (Kindle Edition), 1963.
- Foote, Shelby, The Civil War, A Narrative: Fort Sumter to Perryville. New York: Vintage Books, 1958.
- Freeman, Douglas Southall, Lee. Scribner, (Kindle Edition), 2008.
- Linedecker, Clifford L. (ed.), Civil War A to Z. New York: Ballantine Books, 2002.
- Long, E.B. with Long, Barbara, The Civil War Day by Day. New York: Da Capo Press, Inc., 1971.
- Longacre, Edward G. (Patricia L. Faust ed.), Historical Times Illustrated Encyclopedia of the Civil War. New York: Harper & Row, 1986.
- Longstreet, James, From Manassas to Appomattox: Memoirs of the Civil War in America. Philadelphia: J.B. Lippincott Co. (Kindle Edition), 1895.
- McMurry, Richard M. (Patricia L. Faust ed.), Historical Times Illustrated Encyclopedia of the Civil War. New York: Harper & Row, 1986.
- McPherson, James M., Battle Cry of Freedom: The Civil War Era. Oxford History of the United States Book 6, Oxford University Press (Kindle Edition), 1988.
- Pollard, Edward A., Southern History of the War (facsimile of the 1866 edition). New York: Fairfax Press, 1990.
- Sears, Stephen W., Lincoln’s Lieutenants: The High Command of the Army of the Potomac. Boston, New York: Houghton Mifflin Harcourt Books, (Kindle Edition), 2017.
- Wert, Jeffry D. (Patricia L. Faust ed.), Historical Times Illustrated Encyclopedia of the Civil War. New York: Harper & Row, 1986.